Process of chlorinating indigo.



UNITED sTATEs PATENT oEEIoE.

ALBRECHT SCHMIDT AND ERICH 'KR ONHOLZ, OF HOOHST-ON-THE MAIN, GERMANY,- ASSIGNORS TO FARBWERKE VORM. MEISTER LUCIUS .& BRUNING, OF HOCHST-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

PROCESS OF CHLORINATING INDIGO- Specification of Letters Patent.

Patented Feb. 13, 1906.

Application filed February 28, 1905. Serial No. 247,775.

To all whom it may concern: Be it known that we, ALBRECHT SCHMIDT, P11. D., chemist, a citizen of the Em ire of Germany, and Enron KRoNHoLz, P -D.,

white or indigo, preferably with some diluent, into a paste, to which is added, while stirring, a quantity of sulfurylchlorid, according to the degree of chlorination desired:

Exam Is I .-Three hundred and fifty parts, by weig t, of indigo-white, referably containing some dry hydrosulfit K into two thousand parts, by weight, of tetracarbonchlorid or other suitable indifferent liquid solvent-such, for instance, as carbon bisulfid and the likeand treated, while stir ring, with six hundred and seventy-five parts,

by Wei ht, of sulfurylchlorid. The whole is allowe to stand while bein stirred from time to time until all sulfur lc orid has disap-,

peared. The product 0 chlorination is sepa rated by filtering and distilling off the solvent. If a less chlorinated product is de* sired, less sulfurylchlorid has to be used. For

F, are stirred the indifferent solvent gaseous sulfurylchlorid may be used and directly a plied on indigowhite or indigo or either of t em treated with solid solvents, such as sodium sulfate, ferrous sulfate, and the Carriers, such as iodin, are not absolutely necessary for the action of sulfurylchlorid, but may be used. I

Example II.Twentyseven parts, by weight, (if indigo are divided in about two hundred cubic centimeters of tetra-carbonchlorid and treated, for instance, with sixtyeight a'rts, by weight, of sulfurylchlorid. The w ole is allowed to s and at ordinary temperature until all sulfurylchlorid has disap eared. The product df chlorination is iso ated in the usual manner, The chlorinated indigoes thus obtained dye, accordin to the degree of chlorination, redder an clearer than indigo andpf a similar shadeas the corresponding bromifiated products.

Having now described our invention, what we claim is The process herein described forjthe manufacture of chlorinated indigo dyestuffs, which consists in treating an indigo'body with sulfurylchlorid.

In testimony that e claim the foregoing as our mvention we have signed our names in presence of two subscribing witnesses.

ALBRECHT SCHMIDT. ERICH KRONHOLZ.

Witnesses JEAN GRUND, CARL -GRUND. 

